Abstract:

The influence of the molecular structure of polyvinyl alcohol, including the degree of polymerisation and the degree of alcoholysis, on the adhesion of PVA to pure polyester, pure cotton, and polyester/cotton-blend fibres were investigated by using a method on impregnated roving. The adhesion is evaluated in terms of the maximum strength and work-to-break of the rovings. It was found that the molecular structure has evident influence on the adhesion. No matter what type of tested fibre was used as substrates, the adhesion increased with the increase in the degree of polymerisation. However, it seems that the greatest effect on enhancing the adhesion is reached when the degree of polymerisation exceeds 1700. The degree of alcoholysis of PVA shows less effect on the adhesion than the degree of polymerisation does. The influence of the molecular structures of PVA on the adhesion of PVA-starch blends to fibres is less than that of PVA alone. We also discuss and analyse the experimental results from the point of view of the adhesion theory, especially from the type of failure, dispersion forces and internal stress on interfaces, and cohesive forces of the adhesive layer.